古脊椎动物学报2023，Vol.61Issue(2)：142-160,19.DOI:10.19615/j.cnki.2096-9899.230308
中国中新世轭齿象类新材料及有关分类厘定
New zygolophodonts from Miocene of China and their taxonomy
摘要
Abstract
The zygodont proboscideans from the Miocene strata of China are widely distributed.However,the materials are scarce,and their classification has experienced a longtime controversy,from the chaotic state of multiple Zygolophodon species to the only one species,Zygolophodon gobiensis.The combined species Z.gobiensis comprises both the gracile type with a high degree of zygodonty and the robust type that is between the typical bunodont and zygodont morphology.Recently,as the robust type has been re-allocated to another genus Miomastodon and new fossil remains were discovered,it is necessary to further evaluate and classify the zygodont proboscideans from the Miocene of China.In the present paper,we restudied the previously published zygodont specimens of the gracile type,as well as several unpublished Mammutidae specimens.The former including Z.nemonguensis,Z.gromnovae,Z.jiningensis,Z.chinjiensis and two specimens of Gomphotherium xiaolongtanensis,represents Zygolophodon in the original sense in China.In these specimens,the tip of the loph(ids)are sharp.The anterior and posterior pretrite central conules are absent or very weak,and the anterior and posterior crescentoids are sharp and slender.The posttrite mesoconelets are well subdivided and the zygodont crests are developed.In buccal view,the loph(id)s are"A-shaped"and the interloph(id)s are"V-shaped".Their molar morphology resembles that of Z.turicensis,and hereby,they were identified as Zygolophodon cf.Z.turicensis.Several unpublished specimens from Hezheng,Gansu,Tunggur,Nei Mongol,Tongxin,Ningxia and Junggar,Xinjiang exhibit a lower degree of zygodonty,corresponding to the"robust type of Zygolophodon"in which the molar morphology is between the typical bunodonts and zygodonts.The pretrite crescentoids are thicker than Zygolophodon cf.Z.turicensis,and the pretrite central conules usually present on the first and second interloph(id)s.According to the stratigraphic age and characteristics,two species,Miomastodon gobiensis and Mio.tongxinensis were identified.The anterior and posterior pretrite crescentoids of Mio.tongxinensis are weaker and the pretrite central conules are larger than Mio.gobiensis.Geographical distribution indicates that Miomastodon is the predominant member of zygolophodonts in the Early and Middle Miocene in northern China.The discovery of new materials and the reclassification of zygolophodonts provide further evidence for dispersal of Mammutidae from Eurasia to North America and the evolutionary relationships among the species of the family Mammutidae in China.关键词
中国/中新世/玛姆象类/轭齿象属/中新乳齿象属Key words
China/Miocene/Mammutidae/Zygolophodon/Miomastodon分类
生物科学引用本文复制引用
张晓晓,杨絮,孙燕,王洪江,杨蓉,陈善勤,王世骐,李虹..中国中新世轭齿象类新材料及有关分类厘定[J].古脊椎动物学报,2023,61(2):142-160,19.基金项目
中国科学院战略性先导科技专项(编号:XDB26000000,XDA20070203)资助.We thank Chen Guan-Fang,IVPP,China,for providing unpublished material collected from Nei Mongol,as well as a detailed introduction and discussion of the fossil locality.We thank Dr.Xiong Wu-Yang,IVPP,China,for his help in literature.This work was supported by the Chinese Academy of Sciences(grant nos.XDB26000000,XDA20070203,QYZDY-SSW-DQC022,GJHZ1885)and the Second Tibetan Plateau Scientific Expedition and Research(grant no.2019QZKK0705). （编号:XDB26000000,XDA20070203）
